1. Field of the Invention
The present invention relates to an optical lens system, and more particularly to a miniaturized optical lens system used in electronics.
2. Description of the Prior Art
In recent years, since the optical lens system has become smaller in size, and due to advances in semiconductor manufacturing, the electronic sensor of a conventional digital camera is typically a CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor) sensor, the pixel size of sensors has been reduced gradually, and miniaturization has become the trend of modern electronic products. Therefore, the miniaturized optical lens system with good image quality is still the trend of the mainstream market.
In order to correct aberrations, conventional miniaturized lens systems mostly consist of three lens elements, and one of the typical structures is the positive-negative-positive Triplet type. However, when the size of the lens assembly is reduced substantially, less space is available for constructing the optical system, making it difficult to incorporate three lens elements into the optical system. Furthermore, the lens elements must become thinner, causing poor homogeneity of the plastic material within the lens elements manufactured by injection molding process.
Hence, only the optical lens system with two lens elements is feasible in order to effectively reduce the total track length of the optical lens system. Additionally, in order to correct aberrations, the aperture stop is normally located in the front of the optical system. However, the second lens element of this optical lens system is biconcave, which performs poorly than a meniscus lens element in terms of aberration and astigmatism corrections.
Therefore, the present invention is aimed at providing an easy-to-manufacture miniaturized optical lens system which can effectively reduce the total track length of the optical lens system and provide great image quality.
The present invention mitigates and/or obviates the afore-mentioned disadvantages.